When engaging in weight-control (fitness/fat burning) types of exercise, a person is expected to attain approximately 60% of his or her maximum heart rate. For 20-year-olds, this rate is approximately 120 bpm. A simple random sample of thirty 20-year-olds was taken, and the sample mean was found to be 107 bpm, with a standard deviation of 45 bpm. Researchers wonder if this is evidence to conclude that the expected level is actually lower than 120 bpm. Report a 95% confidence region for the mean level of heart rate for this group. the mean level of heart rate is greater than 117.67 the mean level of heart rate is lower than 120.96 the mean level of heart rate is lower than 114.47 the mean level of heart rate is greater than 114.47